The pool of lenders offering sub-4% fixed-rate deals has taken a significant hit. All of the biggest banks, namely Barclays, HSBC, Lloyds Bank, NatWest and Santander, have increased rates since the start of March.

According to Moneyfactscompare data, year-on-year average mortgage rates across the two-, five- and 10-year fixed sectors have fallen, but recent increases have pushed the average two- and five-year rates above 5%.

Rachel Springall, finance expert at Moneyfactscompare.co.uk, said: “Borrowers looking for the lowest fixed rates will be disappointed to see the demise of sub-4% mortgages, but they are not sustainable with swap rates increasing.

“Lenders look at margins very carefully, so it would be unwise to price their deals too low if the expectations are for interest rates to rise, even if over the short term.

“It really is too early to tell what might happen, but borrowers searching for a new deal should seek advice if they are concerned about rising costs.

“It is still important to secure a fixed deal compared to a high revert rate, as almost £300 could be saved each month in repayments, and existing borrowers could lock into a new deal six months in advance.”

The average standard variable rate (SVR) is currently 7.13%. Calculations are based on a £250,000 mortgage over a 25-year term on a repayment basis. The SVR repayment would be around £1,787 per month, versus £1,502 per month on 5.28% two-year fixed rate.